Siemens SINUMERIK 840Di sl Commissioning Manual page 429

● For operation with feedforward control:
Encoder limit frequency monitoring
Monitoring of the limit frequency of the encoder of a machine axis.
● MD36300 $MA_ENC_FREQ_LIMIT (encoder limit frequency)
Error reaction:
● Alarm "21610 Encoder frequency exceeded"
● IS DB31, ... DBX60.2 "Encoder limit frequency exceeded 1"
● IS DB31, ... DBX60.3 "Encoder limit frequency exceeded 2"
and stopping the machine axis using a speed setpoint ramp whose characteristic curve is set
in the following machine data:
● MD36610 $MA_AX_EMERGENCY_STOP_TIME (braking ramp time when errors occur)
Causes of error/error handling:
After the axes have stopped, the position control is automatically resumed.
NOTICE
The axis affected must be re-referenced.
Encoder zero mark monitoring
The zero mark monitoring of the encoder of a machine axis checks whether pulses were lost
between two zero mark passes. The following machine data is used to enter the number of
detected zero mark errors at which the monitoring is to respond:
● MD36310 $MA_ENC_ZERO_MONITORING (Zero-mark monitoring)
Special feature:
A value of 100 will additionally disable the hardware monitoring of the encoder.
Error reaction:
● Alarm "25020 Zero mark monitoring"
and stopping the machine axes using a speed setpoint ramp whose characteristic curve is
set in the following machine data:
● MD36610 $MA_AX_EMERGENCY_STOP_TIME (braking ramp time when errors occur)
Causes of error/error handling:
● MD36300 $MA_ENC_FREQ_LIMIT [n] (encoder limit frequency) set too high.
● Encoder cable damaged.
● Encoder or encoder electronics defective.
Manual
Commissioning Manual, 05/2008, 6FC5397–4CP10–4BA0
MD32810 $MA_EQUIV_SPEEDCTRL_TIME (equivalent time constant of speed control
loop for feedforward control) or if the machine data is imprecisely set, the MD36400
$MA_CONTOUR_TOL must be enlarged.
NC Commissioning with HMI Advanced
11.5 Axes and spindles
429